Bullet with increased effective range

ABSTRACT

The present invention relates to a bullet with an increased effective range. The bullet includes a front end portion ( 10 ) having a hemispherical shape, a recess portion ( 20 ) connected to a rear end of the front end portion ( 10 ) and having a curved surface that is recessed inward, an inclined portion ( 30 ) connected to a rear end of the recess portion ( 20 ) and inclined at a predetermined angle (A) with respect to a horizontal line, a stepped portion ( 40 ) connected to a rear end of the inclined portion ( 30 ) and inclined at a predetermined angle (A′) with respect to the horizontal line, and fluid inducing grooves formed from the rear to a rear end surface of the bullet ( 1 ). Thus, when the bullet passes through underwater, super cavitation may be more effectively generated and maintained for even longer to significantly increase the effective range of the bullet.

This application is a national stage application of PCT/KR2017/003939filed on Apr. 12, 2017, which claims priority of Korean patentapplication number 10-2016-0145967 filed on Nov. 3, 2016. The disclosureof each of the foregoing applications is incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a bullet with an increased effectiverange, and more particularly, to a bullet with an increased effectiverange, in which super cavitation is effectively generated around thebullet when the bullet is shot into air or water to increase theeffective range, thereby improving accuracy (accuracy rate) of striking.

DESCRIPTION OF THE RELATED ART

A bullet loaded in and shot from a projectile is composed of gunpowdergenerating firing energy by explosion and a warhead flying to a targetby the firing energy. When the bullet is manufactured, a jacket made ofa copper alloy is generally manufactured in a conical shape having aspace therein through mechanical machining such as forging, and then,melted metal such as lead is injected into the inner space of the jacketby using a nozzle.

Also, a bullet having a structure, in which a groove is formed in anouter circumferential surface of the bullet so that flying resistance isreduced to increase an effective range when the bullet is shot to fly inair and also to improve accuracy, and a groove deeply recessed in afront inner direction is formed in a rear surface of the bullet to fillgunpowder into the groove, is being used.

However, although the bullet having the above-described structure isincreased in effective range and improved in accuracy when shot in air,if the bullet is used as a bullet for underwater launch, the deep grooveformed in the rear surface of the bullet may generate excessive vortex.Thus, the bullet having the above-described structure is not suitablefor a bullet for underwater.

Also, in the bullet into which a soft metal such lead is filled, thelead filled into the bullet is instantly compressed and then expandedtoward the jacket by explosive power of the gunpowder, and thus, thejacket is expanded also to increase a contact between a barrel and thebullet and effectively transfer the explosive power to the bullet,thereby increasing the effective range. However, if the bullet havingthe above-described structure is used for the underwater launch,although the explosive power is effectively transferred to the bullet,the jacket forming an outer appearance of the bullet is contracted by awater pressure applied to a front surface of the bullet when the bulletadvances in the underwater, and thus, the lead filled in the jacket ispushed to a rear side of the bullet. As a result, the jacket is deformedto significantly deteriorate the accuracy.

Due to the above-described reasons, when the bullet advances in theunderwater, the effective range is extremely shortened, and also theaccuracy is reduced when compared to the case in which the bullet fliesin air. To solve this problem, European Patent Application No. 2053342and US Patent Application No. 2011-0297031 are disclosed, in which astepped portion or an inclined surface is formed at the front of abullet as illustrated in FIG. 1A to artificially generate bubbles in afront surface of the bullet and cause super cavitation, in which anouter circumferential surface of the bullet is surrounded by thebubbles, by taking reversely disadvantage of the bubbles when the bulletadvances in underwater, thereby reducing water resistance acting on thesurface of the bullet and improving an effective range of the bullet.

However, when the bullet is gradually reduced in advancing speed whilethe bullet advances in the underwater, air constituting the bubbles isreabsorbed into the water. Thus, since the effective super cavitationaround the bullet as described above is not generated to graduallyreduce a size of a cavity existing between the outer circumferentialsurface and the water. Furthermore, as illustrated in FIG. 1B, when thewater contacts the outer circumferential surface of the bullet, aresistance reduction effect of the water due to the super cavitation isgone to sharply reduce the advancing speed of the bullet, and thereby toreduce the effective range. Therefore, development of a bullet in whichthe super cavitation generated around the bullets is maintained for evenlonger to increase the effective range of the bullet is being required.

SUMMARY OF THE INVENTION Problem to be Solved of the Invention

The present disclosure is contrived to solve the foregoing problems ofthe bullet according to the related art, and an object of the presentinvention is to provide a bullet having a structure in which supercavitation is more effectively generated around the bullet flying in airor underwater and maintained for even longer to increase an effectiverange.

Means for Solving Problems

According to an aspect of the present invention, there is provided abullet with an increased effective range, which has a streamlined shapeon the whole and is shot into air and underwater to strike a target, thebullet including: a front end portion having a hemispherical shape; arecess portion connected to a rear end of the front end portion andhaving a curved surface that is recessed inward; an inclined portionconnected to a rear end of the recess portion and inclined at apredetermined angle with respect to a horizontal line; a stepped portionconnected to a rear end of the inclined portion and inclined at apredetermined angle with respect to the horizontal line; and fluidinducing grooves formed from the rear to a rear end surface of thebullet.

The angle of the stepped portion may be greater than the angle of theinclined portion.

An installation hole communicating backward may be formed in the bullet,and a projectile and a rear assembly may be inserted into and assembledwithin the installation hole.

A front end portion, a recess portion, an inclined portion, and astepped portion, which respectively have the same shape as the front endportion, the recess portion, the inclined portion, and the steppedportion, may be formed on the front of the projectile.

The bullet may further include: a main body having a cylindrical shape,in which the fluid inducing grooves are formed in the rear thereof, aninstallation hole passing in a front and rear direction thereof isformed therein, and a bubbling groove is formed in an outercircumferential surface thereof; a front assembly inserted and installedto the front of the installation hole so as to be exposed to a frontside of the main body; and a rear assembly assembled with the rear ofthe installation hole, wherein the front assembly may include: aprotrusion part protruding to the front side of the main body; and aninsertion part disposed at a rear side of the protrusion and insertedinto the installation hole.

At least one coupling groove may be formed in the projectile or theinsertion part.

The front of the installation hole may have a diameter greater than thatof the insertion part so that the front of the installation hole isspaced a predetermined distance from the insertion part.

Effect of Invention

According to the present invention, when the bullet flies in the air,the air may be uniformly induced to the central portion of the rear endsurface of the bullet by the air inducing groove formed in a rear sideof the bullet to generate turbulence and prevent the bullet from beingshaken. Thus, the bullet may be stably flied to improve the effectiverange and accuracy. When the bullet advances in the underwater, thesuper cavitation may be more effectively generated by the front endportion, the recess portion, the inclined portion, and the steppedportion, which are provided on the bullet, to significantly increase thesize of the cavity between the surface of the bullet and the water whencompared to that of the bullet according to the related art and also maybe maintained for even longer to significantly increase the effectiverange of the bullet. Therefore, the bullet may be stably flied andimproved in accuracy.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1a and 1b are views illustrating an example in which supercavitation is generated around a bullet and then dissipated;

FIG. 2 is a perspective view illustrating an example of the bullethaving an increased effective range according to the present invention;

FIG. 3 is a partial enlarged view of a front end portion, a recessportion, an inclined portion, and a stepped portion according to thepresent invention;

FIGS. 4a and 4b are views illustrating an example in which the supercavitation is generated around the bullet having the increased effectiverange according to the present invention;

FIG. 5 is an exploded perspective view illustrating a first embodimentassociated with manufacturing of the bullet having the increasedeffective range according to the present invention;

FIG. 6 is a cross-sectional view of FIG. 5;

FIG. 7 is an exploded perspective view illustrating a second embodimentassociated with manufacturing of the bullet having the increasedeffective range according to the present invention; and

FIG. 8 is a cross-sectional view illustrating the spindle and thesusceptor of FIG. 7.

EXPLANATION OF MARKS

1: a bullet 1A: an installation hole 1B: a bubbling groves 10: a frontend portion 20: a rear end of the recess portion 30: an inclined portion40: a stepped portion 50: a fluid inducing grooves 60: a projectile 61:a front end portion 62: a recess portion 63: an inclined portion 64: astepped portion 65: a coupling grooves 70: a rear assembly 100: a mainbody 110: an installation hole 120: a bubbling groove 200: a frontassembly 210: a protrusion part 220: an insertion part 221: a couplinggrooves 300: a rear assembly A: a predetermined angle A`: angle of astepped portion CL: virtual center-line of a bullet L1: length of a rearend of the recess portion L2: length of an inclined portion

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, configurations and effects of the present invention will bedescribed in more detail with reference to the accompanying drawingsillustrating preferred embodiments.

The present invention is to provide a bullet in which super cavitationis effectively generated around an outer circumferential surface of thebullet and maintained for even longer while the bullet advances in airand underwater to increase an effective range. For this, as illustratedin FIGS. 2 and 3, the bullet 1 of the present invention includes a frontend portion 10, a recess portion 20, an inclined portion 30, a steppedportion 40, and a fluid inducing groove 50 in order from a front endthereof.

Also, for convenience of description, a case in which the bulletadvances in the underwater, instead of a case in which the bullet fliesin the air, will be described below.

As illustrated in FIG. 2, the front end portion 10 having ahemispherical shape is provided on a front end of the bullet. When thebullet 1 is shot into air to advance in the underwater at a high speed,a flow of the water may be guided along the hemispherical shape of thefront end portion 10 due to the structure of the front end portion 10,thereby improving advancing performance of the bullet 1 in theunderwater. Also, the water flows along a tangential direction of thefront end portion 10 having the hemispherical shape at the end of thefront end portion 10 and then be spread outward. Thus, the supercavitation may be easily generated at the end of the front end portion10 of the bullet 1.

Also, the recess portion 20 having a curved surface that is recessedinward as illustrated in FIG. 3 is provided on a rear side of the frontend portion 10 so that the end of the front end portion 10 becomes aninflection point. As a result, a pressure of the water is suddenlyreduced at the recess portion 20, and thus, the air dissolved in thewater is deformed into bubbles by a low pressure (vacuum state) toaccelerate generation of an empty space, which is generated by the supercavitation, between the outer circumferential surface of the bubble 1and the water, i.e., cavity, thereby reducing resistance of the wateracing on the bullet 1 and improving the effective range of the bullet 1.Thus, the bullet 1 may stably advance in the underwater to improve theaccuracy of the striking.

Since the recess portion 20 having the curved shape that is recessedinward is provided on a rear side of the front end portion 10 asdescribed above, the water flowing around the outer circumferentialsurface of the bullet 1 may be farther away from the outercircumferential surface of the bullet 1. Thus, the super cavitation maybe maintained for even longer, and the effective range may be increasedwhen compared to the bullet (underwater bullet) according to the relatedart.

As illustrated in FIG. 3, the inclined portion 30 forming a plane thatis inclined at a predetermined angle A with respect to a virtual centralline CL of the bullet 1 to extend backward is provided on a rear side ofthe recess portion 20 to prevent a distance between a surface of thecavity formed around the bullet 1 and the outer circumferential surfaceof the bullet 1 from being suddenly reduced and guide the flow of thewater to a rear side of the bullet 1 so that the bullet 1 stablyadvances. Here, the inclined portion 30 may have a length L2 greaterthan that L1 of the recess portion 20.

Also, the cavity may be reduced in size while the water flows along theinclined portion 30, and thus the water may approach the surface of thebullet 1. In this case, the advancing speed of the bullet 1 may besignificantly reduced. To prevent this phenomenon from occur in thepresent invention, as illustrated in FIGS. 4a and 4b , the steppedportion 40 forming a plane that is inclined at a predetermined angle A′with respect to the virtual central line CL of the bullet 1 may extendfrom an end of the inclined portion 30. Here, the angle A′ of thestepped portion 40 may be greater than that A of the inclined portion30.

The cavity around the bullet 1, which comes close up to the surface ofthe bullet 1 by the above-described stepped portion 40, may meet thestepped portion 40 to regenerate the super cavitation, thereby againincreasing a size of the cavity around the bullet 1 and reducing theresistance of the water around the bullet 1.

A streamlined portion (not shown) forming a horizontal surface togetherwith an outwardly protruding surface of the bullet 1 extends at a rearside of the stepped portion 40. The flow of the water is guided by thestreamlined portion to smoothly advance in the underwater. Three fluidinducing grooves 50 are formed from the rear of the streamlined portionto a rear end surface approximately vertically formed on the rear of thestreamlined portion at the end of the streamlined portion. When thebullet 1 is shot to fly in the air and advance in the underwater, theflows of the air and water are uniformly induced to a center of the rearend surface of the bullet 1 and forms turbulence by the fluid inducinggroove 50 so that the shaking of the bullet 1 is prevented to stablyfly. Thus, the accuracy rate of the bullet 1 may be improved, and theflying resistance may be reduced to help the extension of the effectiverange.

As illustrated in FIG. 2, the three fluid inducing grooves 50 isinclined at the same an angle and in the same direction with respect toa straight line passing through the center of the rear end surface ofthe bullet 1, and ends of the fluid inducing grooves 50 may be spaced apredetermined distance from each other from the center of the rear endsurface of the bullet 1.

When the bullet 1 having the above-described structure and the increasedeffective range is manufactured, the front end portion 10, the recessportion 20, the inclined portion, and the stepped portion 40 may beintegrally manufactured with the rear of the bullet 1 or be assembledwith the rear of the bullet 1. Hereinafter, each of the cases will bedescribed as one exemplary embodiment.

Embodiment 1

According to Embodiment 1, as illustrated in FIGS. 5 and 6, an outershell of a bullet 1 is made of a metal such as a copper alloy. Asdescribed above, a front end portion 10, a recess portion 20, aninclined portion 30, a stepped portion 40, a streamlined portion, and afluid inducing groove 50 are sequentially formed on an outercircumferential surface and a rear end surface of the bullet 1. Also, aninstallation hole 1A extending backward is formed along a virtualcentral line CL within the bullet 1. A bubbling groove 1B having arecessed shape in a circumferential direction is formed in a portion ofthe outer circumferential surface, and a front portion of a projectile60 having an outer circumferential surface with the same outercircumferential surface as that of each of the front end portion 10, therecess portion 20, the inclined portion 30, and the stepped portion 40,which are formed on the outer shell of the bullet 1, is inserted andinstalled in the installation hole 1A. A rear assembly 70 is insertedinto and assembled with a rear side of the projectile 60 at apredetermined distance, and an empty space is formed between theprojectile 60 and the rear assembly 70 to reduce a weight of the bullet1.

Here, the projectile 60 inserted into and installed in the installationhole 1A formed in the outer shell of the bullet 1 is manufactured byusing a soft metal such as tungsten or a tungsten alloy that hasstiffness superior to that of the outer shell. At least one couplinggroove 65 is formed at a rear side of the projectile 60. Here, the outershell made of a relatively soft material when compared to the projectile60 may be press-fitted into the coupling groove 65 by applying forcefrom the outside of the outer shell of the bullet 1, and thus, theprojectile 60 inserted into the installation hole 1A may be firmly fixedinside the outer shell of the bullet 1.

According to the above-described material characteristics and structure,when the bullet 1 is shot to enter into the water and approach a target,the outer shell made of the soft metal is ruptured by an impact, andthus, the projectile 60 installed in the outer shell is out of the outershell to penetrate the target. Here, since a front end portion 61, arecess portion 62, an inclined portion 63, and a stepped portion 64 areformed also on the projectile 60, resistance force generated while thebullet 1 strikes the target may be significantly reduced to improve thestriking performance to the target.

Embodiment 2

As illustrated in FIGS. 7 and 8, Embodiment 2 relates to a bullet 1having a structure in which a main body 100, a front assembly 200, and arear assembly 300, which constitute the bullet 1, are separatelymanufactured and then assembled with each other to manufacture thebullet 1. The main body 100 has a cylindrical shape, and an installationhole 111 passing in a front and rear direction of the main body 100 isformed in an inner center of the main body 100. A bubbling groove 120having a recessed shape in a circumferential direction is formed in aportion of an outer circumferential surface of the main body 100, andthree fluid inducing grooves 60 as described above are formed in a rearside of the main body 100.

Here, a front diameter of the installation hole 110 has a greater thanthat of an insertion part 220 so that the front of the installation hole110 is spaced a predetermined distance from the insertion part 220 ofthe front assembly. As a result, the bullet 1 may be reduced in weight.

Also, when the front assembly 200 is installed on the main body 100, thefront assembly 200 fitted into and installed in the front of theinstallation hole 110 is constituted by a protrusion part 210 exposed toa front side of the main body 100 and the insertion part 220 disposed ata rear side of the protrusion part 210 and inserted into theinstallation hole 110 of the main body 100. Here, as described above, afront end portion 10, a recess portion 20, an inclined portion 30, and astepped portion 40 are formed on the protrusion part 210.

Also, the rear assembly 300 is inserted and installed in the rear of theinstallation hole 110 formed in the main body 100 so as to be spaced apredetermined distance from a rear end of the front assembly 200. Sincean empty space is formed between the front assembly 200 and the rearassembly 300, the bullet 1 may be reduced in weight.

Also, the front assembly 200 is manufactured by using a hard metal suchas tungsten or a tungsten alloy that has stiffness superior to that ofthe main body 100 made of a material such as a copper alloy. LikeEmbodiment 1, since at least one coupling groove 221 is formed in anouter circumferential surface of the rear of the insertion part 220 ofthe front assembly 200, the main body 100 and the front assembly 200 maybe firmly coupled to each other.

Due to the above-described material characteristics and structure of thebullet 1, when the bullet 1 is shot to enter into the water and approacha target, the front assembly 200 may be maintained in shape as it iswithout being damaged even though an impact on the water or the targetoccurs. Thus, the superior striking performance of the bullet 1 to thetarget may be secured. As described above, the present invention mayprovide the bullet having the increased effective range and superiorstriking performance by more effectively generating the super cavitationand maintaining the super cavitation for even longer when the bulletpasses through the air or underwater.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present invention. Thus,it is intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A bullet with an increased effective range, whichhas a streamlined shape on the whole and is shot into air or underwaterto strike a target, the bullet comprising: a front end portion having ahemispherical shape; a recess portion connected to a rear end of thefront end portion and having a curved surface that is recessed inward;an inclined portion connected to a rear end of the recess portion andinclined outwardly at a predetermined angle with respect to a horizontalline; a stepped portion connected directly to a rear end of the inclinedportion and inclined outwardly at a predetermined angle with respect tothe horizontal line; a streamlined portion connected to a rear end ofthe stepped portion and having an outwardly protruding surface extendedat the rear end of the stepped portion; and a tail portion connected tothe streamlined portion and having an outer surface and a rear surface;wherein the tail portion has fluid inducing grooves formed from the rearsurface to the outer surface of the tail portion, and the angle of thestepped portion is greater than that of the inclined portion.
 2. Thebullet of claim 1, wherein an installation hole communicating backwardis formed in the bullet, and a projectile and a rear assembly areinserted into and assembled within the installation hole.
 3. The bulletof claim 2, wherein a front end portion, a recess portion, an inclinedportion, and a stepped portion, which respectively have the same shapeas the front end portion, the recess portion, the inclined portion, andthe stepped portion, are formed on the front of the projectile.
 4. Thebullet of claim 1, further comprising: a main body having a cylindricalshape, in which the fluid inducing grooves are formed in the rearthereof, an installation hole passing in a front and rear directionthereof is formed therein, and a bubbling groove is formed in an outercircumferential surface thereof; a front assembly inserted and installedto the front of the installation hole so as to be exposed to a frontside of the main body; and a rear assembly assembled with the rear ofthe installation hole, wherein the front assembly comprises: aprotrusion part protruding to the front side of the main body; and aninsertion part disposed at a rear side of the protrusion and insertedinto the installation hole.
 5. The bullet of claim 2, wherein at leastone coupling groove is formed in the projectile.
 6. The bullet of claim4, wherein the front of the installation hole has a diameter greaterthan that of the insertion part so that the front of the installationhole is spaced a predetermined distance from the insertion part.